Network Analysis of Turbine and Feedwater Systems of the 'Fugen' Nuclear Power Plant

作者：Mochizuki Hiroyasu^*; Tsukamoto Takateru

来源：Journal of Nuclear Science and Technology, 2011, 48(5): 786-796.

DOI：10.3327/jnst.48.786

• turbine and feedwater systems
• balance of plant
• feedwater heater
• plant dynamics
• network analysis
• flashing
• two-phase flow
• flow regime

The present study describes the thermal-hydraulic network analysis of the turbine and feedwater systems of the 'Fugen' reactor. Turbines, feedwater heaters, and corresponding piping systems are modeled using the network calculation code NETFLOW++ and thermal-hydraulic conditions are calculated using the coupled numerical model. As a result of the calculation, distributions of important characteristics of the single-phase flow and two-phase flow in the piping such as pressure and void fraction are clarified. Flow patterns in the piping were investigated using the calculated result. It was found that the state of the coolant in the drainpipe changes from saturated liquid at the inlet to a two-phase flow with a large void fraction at the connection to the feedwater heaters. This is attributed to the pressure difference between the inlet and outlet of the drainpipes. Even the drainpipe from the moisture separator to the shell of feedwater heater #4 shows a similar behavior, and the flow pattern changes from single phase to slug flow. The steam quality in the extraction line is very high, although a large number of droplets are contained in the flow. Contrary to expectation, these droplets do not completely evaporate in spite of the low-pressure conditions.

• 出版日期2011-5